1. Field of the Invention
The present invention relates to a spiral contactor electrically connected to an electronic component having a connecting terminal such as a BGA or a LGA, and more particularly, to a spiral contactor, a contact sheet having the spiral contactor and a connecting device having the contact sheet, in which a spring constant and a mounting density per unit area can be increased.
2. Description of the Related Art
FIG. 7 is a plan view showing a part of a contact sheet having a spiral contactor of related art, and FIG. 8 is an enlarged plan view of the spiral contactor of the related art.
A contact sheet 1 shown in FIG. 7 has a guide frame 2 composed of a thin insulating sheet with a plurality of spiral contactors 3 regularly arranged on the guide frame 2 in vertical and horizontal directions. As shown in FIG. 8, each spiral contactor 3 is formed of a thin copper plate having substantially a square shape and has a supporting portion 3A which functions as an enclosure and a deforming portion 3B which is notched in a spiral shape in the supporting portion 3A.
The contact sheet 1 is mounted on an insulating substrate having a plurality of through holes regularly arranged in the vertical and horizontal directions. A conductive portion is formed at the periphery and inside of each through hole and the supporting portion 3A of each spiral contactor 3 is electrically fixed to the periphery of each through hole. Also, the deforming portion 3B is located on the through hole and can be elastically deformed in a penetrating direction of the through hole.
If external contactors such as a plurality of spherical contactors (BGA) or cone-shaped contactors CGA provided on a bottom surface of an electronic component such as an IC are tightly pressed in a state in which they are opposite to the plurality of the spiral contactors 3, the external contactors reach into the through holes while pressing the spiral contactors 3. At this time, since the deforming portion 3B of the spiral contactor 3 is elastically deformed and is wound around and contacted to the outside of the external contactor, each spherical contactor and each spiral contactor are electrically connected to each other.
As related art documents related to the above-mentioned spiral contactor, there are Japanese Unexamined Patent Application Publication Nos. 2002-175859, 2003-78078 and 2004-12357.